Island



2 Sheets-Sheet 1.

(No Model.)

V. A. THOMAS. MAST ARM FOR ELECTRIC LIGHTS. N 9. 463,586. Patented Nov. 17,1891.

ITNESSES.

2 t e e h s m e e h s M A d 0 M 0 m Patented Nov. 1'7, 1891.

s m k Ms A m WITNESSES.

UNITED STATES PATENT OFFICE.

' VAN A. THOMAS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR OF ONE-HALF TO ANDREIV D. ROSS, OF SAME PLACE.

MAST-ARM FOR ELECTRIC LIGHTS.

SPECIFICATION forming part of Letters Patent No. 453,586, dated November 17, 1891.

Application filed octoher 6, 1890. Serial No. 367,189. (No model.)

To all whom it may concern:

Be it known that I, VAN A. THOMAS, a citizen of the United. States, residing at- Providence, in the county of Providence and State of Rhode Island, have invented certain new and usefulImprovementsinaOombinedMast-Arm and Conductor for Electric Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such to as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

In the construction and arrangement of mast-arms adapted to carry electric lamps ithas been usual heretofore to conduct the electric current to such lamps by means of insulated flexible conductors. Sometimes, however, the current is conducted from a live or charged track to the lamp, the latter being mounted on a carriage arranged to travel back and forth upon the track, yet at the same time being insulated from it.

The object I have in view is to provide a mast-arm with improved means for electrically connecting arc lamps supported thereon.

To that end my invention consists, essentially, in the combination of a current-conducting double track insulated from the pole and supporting-braces and a movable lampcarrying trolley or carriage mounted on the track andin direct electrical connection therewith, all as will be more fully hereinafter set forth and claimed.

In the accompanying two sheets of drawings, Figure 1 is a side elevation of a mounted mast-arm embodying my improvement. Fig. 2 is a horizontal sectional view taken on line so wof Fig. 1. Fig. 3 is an enlarged side Viewin partial section, showinga manner of connecting the conductor and cut-out box. Fig. 4 is a transverse sectional view taken on line 0 o of Fig. 1. Fig. 5 is a horizontal sectional View showing. the manner of mounting and insulating the outer end of the mast-arm or track. Fig. 6 is an enlarged transverse sec tional view showing the manner of mounting, supporting, and electrically connecting the lamp. Fig. 7 is an enlarged side eleva' tion, in partial section, of the lamp and outer portion of the mast-arm. Fig. 8, Sheet 2, isa transverse sectional View of the track enlarged, showing a preferable manner of suspending the lamp from the mast-arm. Fig. 9 is an enlarged cross-sectional view taken, say,

on line a a of Fig. 1, showing the relation of the cut-out box to the track, &c.' Fig. 10 is a sectional View similar to Fig. 8, the trolley in this case having a protecting-hood attached 6o thereto. Fig. 11 shows, cross-sectionally, a modified form of the track; and Fig. 12 is a transverse sectional View of the track, showing a manner of staying the upper and lateral braces. A

A more detailed description of my improved mast-arm, &c.,'is as follows: Th earrangement, as a whole, is-indicated byA. The mast-arm itself is secured to a pole p, the latter being provided at its upper end with a cross-bar h, .having insulators which carry the main conductors or live wires 6, as common.

The mast-arm consists of two supported and braced tracks a a, of iron or other suitable conducting material. I preferably arrange the tracks or bars a edgewise and parallel with but insulated from each other, the upper edges as drawn being well rounded. The inner end of each track is secured by bolts 0 to a metal bracket Z), which'in turn is secured to the polep. The other or outer ends of the track are supported in insulated or porcelainliued'pookets 25, formed in a metal cap t, the rear portion of which is extended, as at i so as to form a guard or shield for. the trolley, about to be described. I would state that in lieu of the track represented by Figs. 4:, 6, 8,

9, &c., the one shown.in Fig. 11 may be employed. This latter may be made of wroughtiron rolled into an L form or angle-iron. 0 By means of such construction the lower member a serves to greatly stiffen the track in a lateral direction. Obviously other forms may be substituted without departing from the 7 spirit of the invention. In fact, the track shown by Fig. 11 may be inverted, the flange or rim of the trolley-wheels being modified accordingly. An upper tension-brace d is secured to the said cap 25 and pole p, substantially as shown by Fig. 1, thereby supporting the outer end of the mast-arm, &c. If desired,

a screw-threaded turn-buckle d may be emof the wheels quite large, as shown in Figs. 8 p

and 10. The side frames are separated from each other laterally by a block as of insulating material, as vulcanite. The lower ends of the frames 70 are provided each with a lamp-supporting conductor a, which pass into the hood 7L2 and electrically connect, as common, with f;

the lamps mechanism. The trolley 10 is propelled back and forth upon the track by a cord a, passing over sheaves i, secured to the cap 15 and polep, the ends of the cord beingattached l to staples i secured to the block 00. In Figs.

8 and 10 the lamp brate upon a bolt 6 is mounted to swing or vipassing through a yoke q secured to the lower portion of the insulati ing-block 00, thereby relieving the conductors 1 e from strain or pressure.

At the same time the latter may be provided at its lower side with an offset or bend m which in a measure acts to prevent the passage of water into the 1 hood mechanism.

Itwill be seen that the brackets 12 are provided each with a lateral extension I), having a hole 0 passing through it transversely to freely receivealateral or wind brace 0. These latter braces are made of suitable metal, as brass, iron, &c., and also serve as conductors of electricity. The brace is screwed into an elongated nut u, (see Fig. 3,) preferably square in cross-section. An adjustingnut it may also be used. The front ends of the conductor-braces c are secured to the corresponding ends of the adjacent tracks a by bolts 0 or in any other suitable manner. In some cases the extensions 1) of the brackets may be still further stiitened by a wrought-iron brace 10*, secured to the post, the ends being bent, insulated, and drilled to receive the rods 0 and held in place by said nuts n,as shown by dotted lines, Fig. 2. It is not necessary that the arms I) be integral with the brackets as drawn, as obviously they may be independently secured to the post or other adjacent surface.

Intermediate of the cross-bar hand conductors c is located a cut-out box in, secured to the post 19. This box may, however, be as usually constructed. The live wire or conductor e passes into the box and thence out at the bottom at c*, Fig. By means of a short wire a, secured to the nut n, and also to the box by a binding-screw e the currentpasses to the respective nut, brace c, bracket 7), and track a, all being in circuit, but insulated from the other track, brace, 6120. The lateral or wind braces care steadied by means of angle-braces c, which latter also connect with the upper rod (1. The tracks are prevented from lateral vibration by short struts or Spreaders r. These are insulated by suitable material, as vulcanite, at e from the track. In like manner they are also insulated from the rods 0. (See Fig. 12.) By this arrangement it is obvious that the current is prevented from passing from one side to the other bid. the braces c.

Now, assuming that an electric lamp 815 mounted upon my improved mast-arm, the operationof the device would be substantially as follows: The trimmer upon reaching the upper portion of the pole p first cuts out the current from the lamp, 850., by means of the lever 1, attached to the cutout box m, thereby causing the current to pass directly through the box, or he may first by means of the cord u draw the lamp within a convenient workin g distance and then shunt the current from the carbons by means of the switch-lever commonly present in lamps of this class. He next trims the lamp, as usual, then reverses the switch-lever and runs the lamp out, say, to the end of the track, (see dotted lines,lhg. 7,) the trolley, &c., then being protected from the weather by the hood or extension t". It is, however, much safer and better to first cut out the track, &c., by the lever has before stated, as then all the parts can be handledand operated without danger. In such cases the track and connected parts will not be in circuit during the day-time, the attendant being able to control the current at all times by simply moving the lever Z of the cut-out box. From the foregoing it will be apparent that upon opening the circuit by a. corresponding movement of the lever Z the current passes along the live wire 6 into the box m, thence out at the bottom of the box and to the nut n, thereby charging the same side of the mast-arm. The current now flows into the lamp 3 through the medium of the corresponding wheel f, resting upon its charged track a, and conductors k e", and across the arc separating the carbons, and thence from the lower carbon the current passes upwardly through the lamp, as usual, and along the conductors, &c., of the other side of the mechanism or mast-arm, the current finally passing into the lower side of the cut-out box and out at the top, where it communicates with the return-wire 6, thus completing the circuit. It will be seen that the braces 1:, i), and (Z, and also the cap t, are at all times completely insulated from the other portions of the apparatus. 1t is further obvious that the cur rent passes from the track into the lamp irrcspective of its location upon the track.

In order to protect the trolley w in cases where the position of the lamp upon the mastarm may be varied or not carried out to the extreme end of the arm, I preferably employ a hood or guard h*, which is secured to the trolley or carriage itself, as clearly shown by Fig. 10.

I claim as my invention 1. The combination, with a mounted mastarm provided with parallel tracks insulated from each other and electrically connected with the poles of an electric-lighting circuit, of lateral braces, and angle-braces connecting and steadying said lateral braces, sub stautially as specified.

2. The combination, with a mounted mastarm provided with parallel tracks insulated from each other and electrically connected with the poles of an electric-lighting circuit, of lateral braces, angle-braces connecting and steadying said lateral braces, and spreaders for laterally bracing the tracks, as set forth.

3. The combination, with a mounted mastarm provided with parallel tracks insulated from each other and electrically connected, as set forth, of lateral braces, angle-braces for steadying the same, and spreaders for laterally bracing the tracks and insulated from the tracks and from the lateral braces and connected thereto, as set forth.

at. The combination, with a mounted mastarm provided with parallel tracks insulated from each other and electrically connected of a lamp adapted to travel on said tracks by means of a trolley, mechanism for moving the trolley, lateral braces, and angle-braces connecting and steadyiug said lateral braces, substantially as specified.

In testimony whereof I have affixed my signature in presence of two witnesses.

VAN A. THOMAS.

Witnesses 7 CHARLES HANNIGAN, GEo. ll. REMINGTON. 

